Dialkyl sulfides are important industrial chemicals. They can be used as solvents for anhydrous mineral salts, in plating baths for coating metals with gold or silver, and as intermediates for preparing other sulfur-containing chemicals.
Although dialkyl sulfides can be produced by UV-promoted addition of alkyl mercaptans to alkenes, UV reactors may not always be available. Dialkyl sulfides can also be produced as by-products in the production of alkyl mercaptans by the reaction of alkenes and hydrogen sulfide catalyzed by an acid, a base, or supported cobalt/molybdenum, followed by separation from the mercaptans.
However, it has been found that in order to sufficiently increase dialkyl sulfide production in the alkyl mercaptan process, the hydrogen sulfide feed has to be reduced to less than one mole per mole of the alkene feed. Under such condition, a large amount of heat is generated by the reaction creating a problem for controlling the heat in a production plant.
It is therefore desirable to develop a process that utilizes alkyl mercaptans produced in the reaction of alkenes and hydrogen sulfide for the production of dialkyl sulfides. It would be a valuable contribution to the art if a process for increasing the production of the dialkyl sulfide is developed which does not require UV light or a high ratio of alkene to hydrogen sulfide.